Recently, a capsule endoscope having an imaging function and a wireless communication function has made an appearance in the field of the endoscope. After the capsule endoscope is swallowed by a subject person as a subject (human body) for the purpose of an observation (examination), the capsule endoscope moves through the inside (body cavity) of organs such as the stomach and the small intestine according to peristaltic movement of the organ, and the capsule endoscope sequentially takes images using the imaging function until naturally discharged from a living body of the subject.
Image data taken in the body cavity by the capsule endoscope while the capsule endoscope moves in the organs, is sequentially transmitted to an external device provided at the outside of the body by the wireless communication function and stored in a memory provided in the external device. When the subject takes along the external device including the wireless communication function and the memory function, the subject can freely act even after swallowing the capsule endoscope until the capsule endoscope is discharged. After the observation, a doctor or a nurse can make a diagnosis based on the image in the body cavity displayed on display means such as a display from the image data stored in the memory of the external device.
An example of this kind of capsule endoscope includes a swallowable capsule endoscope disclosed in Patent Document 1. In a configuration of the capsule endoscope proposed in Patent Document 1, the capsule endoscope includes a reed switch which is turned on and off by an external magnetic field in order to control drive of the capsule endoscope, and the capsule endoscope is accommodated in a package including a permanent magnet which supplies the external magnetic field. That is, the reed switch included in the capsule endoscope is maintained in an off state under an environment in which the magnetic field having at least predetermined strength is applied, and the reed switch is turned on by decreasing the strength of the external magnetic field. Therefore, the capsule endoscope is not driven in the state in which the capsule endoscope is accommodated in the package. In swallowing the capsule endoscope, the capsule endoscope is taken out from the package and separated from the permanent magnet, so that the magnetic force has no influence on the capsule endoscope to start the drive of the capsule endoscope. In the capsule endoscope having the above configuration, the capsule endoscope can be prevented from being driven when the capsule endoscope is accommodated in the package, the image taking by the imaging function and the image signal transmission by the wireless function are performed after the capsule endoscope is taken out from the package.
Patent Document 1: International Publication No. 01/35813 Pamphlet